Synthesis of a model compound of mappicine ketone based on sulfur-directed 5-exo selective aryl radical cyclization onto enamides

Synthesis of heteroarenes using cascade radical cyclisation via iminyl radicals

“…The mixture was stirred for 15 min at room temperature, 1-[(Z)-3-bromo-2-iodoprop-1-enyl]benzene 14 15 (1.6 g, 4.97 mmol) added, and the reaction heated at 65 • C for 20 h. The mixture was cooled to room temperature and poured into brine (50 cm 3 ), extracted with EtOAc and dried. The solution was evaporated under reduced pressure to give an orange solid which was purified by column chromatography using EtOAc/DCM as eluent to give methyl 6 (7), 293 (13), 281 (4) 268 (30), 192 (7), 181 (6), 133 (9), 115 (14), 91 (100), and 65 (5). Methyl 2-cyano-6-{[(Z)-2-iodo-3-phenylprop-2-enyl]oxy}pyridine-4-carboxylate 17 was also eluted (1.37 (8), 136 (8), 133 (100), 115 (16), 105 (18), 91 (10), 89 (14), 77 (36), 67 (25), 63 (9), 59 (19), 51 (18) and 43 (17).…”

“…8 Synthetic studies towards mappicine using radical cyclisation onto enamides have also been reported. 9 Another group of alkaloids containing the 2,3-dihydro-1Hpyrrolo [3,4-b]quinoline ring system are the recently discovered pyrroloquinazolinoquinoline alkaloids, luotonins A 4, B 5 and E 6 and other congeners. 10 Although the compounds were only isolated four years ago 10 there are already several syntheses of luotonin A, which has proved a popular synthetic target.…”

Synthesis of heterocycles by radical cyclisation

“…Dihydroisoindoles have been synthesised using 5-exo aryl radical cyclisation onto enamides upon treatment of aryl bromide precursors with Bu 3 SnH. 158 A range of substituted benzothiazoles have been prepared by CAN (ceric ammonium nitrate) treatment of arylthiols and cyanobenzenes. 159 SmI 2 -mediated coupling between 1,1-diaryl-2-cyanoethenes and aromatic nitriles yields polysubstituted 3H-pyrroles.…”

Reações de carbociclização radicalar de orto-iodoaliloxibenzoatos derivados de d-glicose e d-galactose e comparação com as reações de seus análogos benzamidas

“…Nestas reações o Bu 3 SnH atua como gerador de um radical inicial no precursor, por meio da quebra homolítica da ligação carbono halogênio, e como redutor do radical cíclico 7 . Halobenzenos substituídos em posição orto com grupos alquenila têm sido amplamente utilizados para síntese de compostos contendo ciclos fundidos a anéis aromáticos [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] . São obtidos os produtos provenientes das ciclizações dos modos endo e/ou exo e os de hidrogenólise (Figura 1).…”